In a mobile communication system for cellular phones, a cellular method is generally used where a base station covers a wide area by combining plural areas (cells) which are ranges where the base station may transmit and receive data to and from a mobile station located therein, and the mobile station may change the base station to be communicated with from one to another while moving.
Recently, the third-generation mobile communication services based on the Direct Sequence Code Division Multiple Access (DS-CDMA) method have been provided. On the other hand, research and development has been actively studied for a next-generation mobile communication scheme that may provide faster communications.
In the 3rd Generation Partnership Project (3GPP), the Long Term Evolution (LTE) has been studied to start its services (see, for example, 3GPP TR25.913 V7.3.0). Further, the LTE-advanced which is an updated version of the LTE has also been studied (see, for example, 3GPP TR36.913 V8.0.1). Further, in the LTE-advanced, a relay station (relay) may be used so as to improve the throughput and characteristics in a skip zone.
In the 3GPP, as configurations of the relay station, it has been considered that the relay station may operate similar to a base station in a normal state and the existence of the relay station may not be recognized by a mobile station. The former configuration is called “Type1” and the latter configuration is called “Type2”.